1. Research Center for Bio-Based Chemistry, Korea Research Institute of Chemical Technology (KRICT), University of Science and Technology (UST), Ulsan 44429, Korea
2. Department of Nanomechanics, Korea Institute of Machinery and Materials (KIMM), University of Science and Technology (UST), 156 Gajeongbuk-ro, Yuseong-gu, Daejeon 34103, Korea
3. Dental Research Institute and Department of Biomaterials Science, Seoul National University, Seoul 110-749, Korea
4. Department of Dentistry, Anam Hospital Korea University Medical Center, Seoul 136-705, Korea